The present invention concerns a stackable container. More particularly, this invention relates to a container having a plug-type closure, wherein when identical containers are stacked one upon another. The plug-type closure acts as a locking device.
In the manufacture of containers designed for marketing household articles such as cleaning products, food products and other commodities, such containers are conventionally made in such a manner that it is difficult to stack them one upon another and maintain the same in stacked arrangement. Considering the conventional metal or plastic cans, for example, these are generally made with flat end walls usually flanged around the edge and of the same diameter from one end to another. Accordingly, when such cans are placed one upon another, there is only a narrow edge-to-edge contact between the flange at the top end of one can and the flange at the bottom end of the overlying can. As a result, such cans or containers can be easily knocked out of position and will slip one from the other until the entire stack collapses. The slipping or falling of cans from an original stacked arrangement could result in great inconvenience and even risk of injury to people adjacent to the stack at that time. Furthermore, cans may be damaged as a result of falling due to ineffective stacking thus leading to economic loss to the merchant. Additionally, if the contents of the can were to contain a material, such as drain cleaner containing lye, a health hazard would result if the can were to be fractured and its contents were to be displaced from the container.
Exemplary of patents concerning stackable cans, containers and the like are U.S. Pat. Nos. 1,552,134; 2,367,300; 2,641,374; 2,978,142; 3,001,564; 3,065,558; 3,091,361; 3,207,359; 3,217,915; 3,587,904; 3,598,271; 3,642,789 and 3,642,169.
In some of the aforesaid patents, the uppermost can or container would have virtually no resistance to falling in the event that the stack is bumped or shaken. Furthermore, many of the stacking systems disclosed above do not employ the container closure as part of the stacking mechanism. In some instances where the container closure is utilized in a stacking function, the closure itself may have to bear all or most of the weight of the containers above it.
It would be advantageous to have a stackable container in which the container closure aids in the stacking of one identical container upon another, but where the closure does not itself bear the weight of the containers above it.